Grinding and polishing apparatus



Nov. 17, 1925 Filed Aprii 9, 1918 5 Sheets-Sheet l.

aumento@ 1,562,068 W. TAYLOR GRINDING AND PCLISHING APPARATUS Filed April 9, 1918 5 Sheets-Sheet 2 Mza Nov. 17 1925.

Wal/11 5562:

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1,562,068 W. TAYLOR GRINDING AND 'POLISHING APPARATUS il 9, 1918 3 Sheets-Sheet 5 Filed Apr Nov. 179 1925.

Wilnr. se z siding); at Leit STAT-ES y @PATENT OFFICE;

WILLIAM rAYLon, or Lnronsrnn, ENGLAND GRINDING ANI) QGLISHING APPARATUS.

Application ed lApril 9, i918- Serial No. 227,533.

m all fic/loin t may concern:

e it linown that l, lllrtnniar TAYLOR, -a

of the l of Great Britain, re-

England, have invented new and useful Improvements in ding and i?olislune' Apparatus (for which I obtained a patent 1n Great Britain. :Id-1,591,

dated Jan. 3l, 1917)?, of which the following is a specication.

rlhis invention relates to apparatus for Agrinding` and polishing spherically, or appr :imately spherically, curved surfaces, particularly the surfaces of lenses, reflectors, and `the like, of the lrind which comprises two co-a'cting members, the surfaces of which are respectively convex-and concave, and either of whichmay be the work while the other is the tool, in combination with means for pressing the members together and for varying such pressure, means adapted 'to move one of the members bodily about the other to effect the rubbing, and means for equalizinp,` the distribution of the rubbing.

In such apparatus it is customary to mount one member, the work or tool, whichever is convex, upon the upper end of 1a vertical spindle by which it may be rotated, and to move the other (concave) member bodily about 'the surface of the lower member 4in vorder tc effect the rubbing or polishingi,the orbit on which the upper member moves being generally eccentric to thejaxis of the As the upper member moves lower member. about the surface of the lower member it rises and falls according` to the 'extent of its movement and lthe radius 'of curvature vof the sphere; and to effect the `bodily motion ofthe upper member while permitting` it to rise and fallin. this manner it is customary to move said upper member by means of a ball-pointed vertical finger engaging a hole or socket at about the centre of said Vupper member, this linger being fir-Ted at the free end of an arm which is pivot'ed about ahoriaontal artis, so that the linger may rise and fall, and is adapted Vto be moved in a which may be circular in plan view, so as to effect the bodily motion of the member, by means of a cranlr or its equivalent. lressure is put on the pivoted arm and linger in order to press the tooland we p For the best class of work the unifor; .l J such pressure is of great import ce. I find. however. that owing?,` 'to the insti-o of the linger and arm, which actuatc the unbe member, their rising and falling result in path lr together.

vvariations of pressure; and further variations occur because the linger does not rise and fall, nor press the uppern'iember, in the direction of the centre of the sphere, butin a direction more or less tangential to the surface thereof. Furthermore, owing to the fact that, although the pivoted arm may movethe upper member and the linger with constant velocity in a path which is circular in plan view, their rising and falling causes the upper member to follow a more or less elliptical path on the surface of the lower member, with the result that the velocity varies at ydifferent parts of the lastanentioned path and the'accuracy of the `grinting or polishing is thereby affected.

. According to the present invention I einploy a pair of rotary driving spindles for actuating,` the respective co--actingg members,

said spindles having their kaises of rotation mutually inclined in the same plane. and mutually intersecting` at substantially the common centre of curvature of the surfaces of the cci-acting members. F or the sake of convenience, this centre is hereinafter termed the principal centre of the apparatus. rfhe one member, hereinafter termed the concern tric member, is mounted upon its spindle vconcentrically (i. e., with the axiso'f rotation of the. spindle passing through the centre lof curvatureand approximately vtlryough the centre of the surface of said member); whilst the other member, hereinafter termed the eccentric member, is attached to its spindle eccentrically' so as to be vadapted for being, moved thereby bodily (and its cen-tre of surface at substantially constant velocity) n and about the surface of the concentric member.

The invention includes other features of construction and arrangement of parts, all

as hereinafter described and specifically differs materiallyY lGO ilk

the tool, each point in the grinding edge of which follows a circular path the position of which relatively to the work remains constant, so that the tool itself has no bodily movement on or about the surface of the work.

ln the accompanying drawings, which illustrate a convenient form of apparatus constructed in accordance with the invention, the machine comprising four units arranged side by side, Figure l is a. vertical section of the machine from front to back, the ection being taken on the plane in which the axes of the two spindles of the pair comprised. in one unit both lie; Figure 2 is a front elevation of the machine, drawn to a smaller scale, the spindles of both groups being shewn for convenience in one plane; Figure 3 is a. view imilar to Figure l, shewing the right hand side of the machine in elevation; and Figure 4l is a view similar to Figure 3 but on a smaller scale and illustrating a construction in which the spindle-carrying frame is formed in two sections pivoted together to provide for varying thc angular relation of the upper and lower spindles.

For the .sake of more ready identification, that spindle which, in each unit coinprised in the example illustrated, actuates the so-called concentric member will be refel-red to as the lower spindle, and that spindle which actuates the so-called eccentric member will be referred to as the upper spindle, such being the generally preferable arrangement shewn in the drawings.

In each pair of rotary driving spindles, is the axis of the lower spindle A and fz/Hg/ the axis of the upper spindle B, the spindle A being vertical whilst the spindle B, which is on a higher lever, is inclined so that its 'axis y/-?/ intersects the axis .fr-x in the point e. The axes of the lower spindles A of the several units extend in one plane, and those of the upper spindles B of the several units likewise extend in one plane. In Figure 9., for the sake of convenience, the frame C of the machine is shewn as broken and the axes 'gf-y of the several upper spindles B are shewn as if extending in a. vertical plane instead of at an inclination to the vertical. In each unit shewn in Figure 2, the concentric7 member mounted on the lower spindle A is omitted, as is also the eccentric member and the means whereby the same is attached to the upper spindle B.

Referring more particularly to the single unit seen in Figure l, the concentric member D is shewn as convex and hemispherical, and as serving to carry a number of convex lenses d which are embedded in a coating of cement adherent to the convex surface of the member, the centre of curvature of the member as a whole being at the point (i. e., the so-called principal centre) whereat the axes x-ai and g/-g/ intersect one another. rllhe concentric member D is removably attached to the spindle A through the medium of a supplementary spindle E which may be integral with the member D itself and which is caused to extend in axial alignment with the spindle A by resting in a chuck or `socket e fast on said spindle; the contiguous ends of the spindle A and supplementary spindle E being cut away obliquely as at e1 so as to become tightly keyed together when the supplementary spindle is dropped into the socl-etc. A number of concentric members D having 'various radii of curvature would as a rule be used interchangeably; the effective length of the supplementary spindle E being in each case such as to ensure substantial coincidence of the centre of curvature of the member D with the principal centre e. In order, however, to enable perfect coincidence to be established, the position of the spindle A lengthwise of its axis may be made adjustable at will; for which purpose, in the example illustrated, the spindle A, which is adapted to slide through its upper and lower bearing f1, f2 in the frame C, rests upon a footstep bearing y carried by a stirrup F which is suspended from a crank-pin g on the inner end of a forwardlyextending horizontal shaft G journalled in a bearing g1 in the frame C, the outer or front end of the shaft Gr having' a crank handle g2 whereby it may be turned to raise or lower the footstep bearing The spindle A is shewn as carrying, between the bearings f1, f2, a worm wheel H1 in mesh with a worm H2 on ay horizontal shaft H which serves in common for driving the lower spindles A. of all the units comprised in the machine.

The grinding or polishing member .l which, in the example illustrated, constitutes the so-called eccentric member, and which is shewn as concave and approximately hemispherical, is so connected with the upper spindle B as to be caused by the revolution of the latter to move bodily in a circular path, and the centre of its surface at constant velocity, over the surface of the work carried by the spindle A, the attachment between the eccentric member J and spindle B being effected at a ball-and-socket joint whereof the ball j is eccentric to the axis of the spindle B so as to revolve around said axis in a path all points of which are at the same distance from the principal centre e. There will thus be no movement of the ball y' longitudinally of the axis `of the spindle. The ball is on the lower end of a rod or finger jl which, extending radially of the principal centre e, is slidable axially through, and clamped by means of a screw j? in, a bearing at the free end of a pivoted Lacasse or hinged arm K, so that the distance of the centre of the ball from the principal centre .e may be permanently adjusted at will to suit eccentric members el of different curvatures and to change correspondingly the radius of the orbit of the ball j, that is, to obtain correspond ngly differing and 'proportionate eccentricities of the ball y' relatively to the axis fy3/. The arm K is pivoted at an axis 7c to a bracket L carried by a crank arm M fast on the spindle B, the axis lying in a plane perpendicular to the axis of said spindle, so that the ball j and member .l are capable of bodily movement in a direction substantially towards and from the principal centre e, whilst the member J is free to accommodate its surface contour to that of the work by movement in any direction about the ball i In order to cause the member J to yexert the requisite pressure upon the work, a spring N is interposed' between4 the arm K and bracket L; this spring, which is housed,

and takes itsabutment, within a tubularY casing a pivoted at nl to the arm K, acts against a plunger n? which bears against ay concave circular segment Z on the bracket L concentric with the axis nl. Hence, by moving the casing n about the axis al, .the vdistance from the axis 7': at which the spring N acts upon the arm K, and, therefore the pressure exerted by the member J, may be varied without altering the stress existing in the spring itself.

The bracket L might be a fixture on the crank arm M, but in the example illustrated is shewn as pivoted thereto at an axis m which extends parallel to the axis @/-3/ so asto intersect the axis 73 perpendicularly; this arrangement permitting of the arm K being swung aside (when the machine is at rest) to Vfacilitate removal of the member J or member D when necessary. The arrange ment also afi'ords'means for varying the eccentricity of the ball j relatively to the axis jz/-y without substantially altering the distance of the ball from the principal centre e; for which purpose a set-screw O which passes through a threaded hole in a lug opposite to the crank arm M is adapted, in the revolution of the spindle B and crank arm M, to bear against a lug 0 on the arm K, the adjustment of the screw O serving to determine the angular position of the arm K about the axis m and, consequently, the eccentricity of the ball y' relativelyfto the axis The spindle B is journalled in upper and lower bearings b1, b2 in the frame C, between which bearings it carries a worm wheel P1 in mesh with a worm P2 on a horizontal shaft P parallelwith the shaft H; the shaft l? serving in common fordriving the upper spindles B of all the units 'comprised in the machine. In Figs. l and 3 the angular position of the upper spindle B clamping the two sections together' after adjustment about said axis.

The improved apparatus is adapted for producing` accurate surfaces corresponding to as much as a hemisphere, and is most economically used upon lenses, or blocks of lenses, of substantially hemispherical form. For this purpose I find that good results are produced when-the angle w between the axes .0c-x and 'L2/gj (measured in their common plane) is made about 200, and when the angle between the axis of the rod 7'1 and the axis y-g/ (measured in their plane) is also madel about 20o.

Y The spindle which carries the work (in the example illustrated, the lower spindle COHlll'rlOll A.) is preferably rotated more slowly than the spindle which carries the tool (in the example illustrated, tlie upper spindlc'B), and in the drawings, the shaft H whereby all the lower spindles A are actuated is shewn as driven from the shaft P whereby all the upper spindles B are actuated, a belt passing for this purpose around a relatively small pulley p on the shaft P and a relatively large pulley 7L on the shaft H. The shaft l? itself may be driven from any convenient source of power (such as, c. g., a shaftnot shewn-extending beneath the machine parallel to the shaft P) by means, for example, ofa belt Q passing around a pulley Q on said shaft; starting-and stopping means being provided such as a jockey pulley r adapted to bear against the belt and mounted upon one arm of a lever R fulcrumed rto the frame C at r1, the other arm of this lever being' coupled by a `link s to the lever' S which is fulcrumed to the frame C at s1 and controlled by a slidable hand- Alever T.

U is a drip tray extending between the end members of the frame C and adapted to receive the drip from the work and tool in each unit comprised in the machine. All the lower spindles A pass through the bottom u of the drip tray, ,vhichserves to carry the upper bearings f1 of all of said spindles, and which is inclined from each end toward a central discharge 'orifice u1. Suitable provision is made for excluding dust or grit from the various bearings, and for lubri-A spherically curved surfaces, comprising a pair of co-acting Work and tool members, one having a convex and the other a concave surface, means for imparting concentric rotary movement to one of said members, means for moving the other of said members bodily in a circular path about an airis which intersects the axis of rotation of the first said member substantially at the common center of curvature of the surfaces of the tivo co-acting members, and means for applying to the member which is moved bodily a force in a direction at an angle to the axis of the movement of said member and substantially toward the. center of curvature of the co-acting member.

2. Apparatus for grinding and polishing spherically curved surfaces, comprising a pair of co-acting Work and tool memoers, one having a convex and the other a concave surface, a pair of rotary driving spindles for actuating said co-acting members, saidL spindles having their axes of rotation mutually inclined in the same plane and intersecting at substantially the common center of curvature of the surfaces of the rso-acting members, one of said co-acting members being mounted concentrically on its driving spindle, and the other of said members being connected to its driving spindle eccentrically, and means for exerting constant pressure on the eccentric member in the direction at an angle to the axis of its spindle and substantially toward the point of intersection of the axes of the driving spindles.

3. Apparatus for grinding and polishing spherically curved surfaces, comprising a pair of coacting ivork and tool members, one having a convex and the other a concave surface, means for imparting a concentric rotary movement to one of said members, and means for moving the other of said members bodily in an eccentric path on and about the surface of the first mentioned member, said moving means including a device adapted to engage and move the said member and being adjustable along a line radial to the common center of curvature of the tu'o coacting members.

l. Apparatus for grinding and polishing spherically curved surfaces, comprising a pair of co-acting Work 'and tool members, one having a convex and the other a concave surface, a pair of rotary driving spindles for actuating said co-acting members, said spindles having their axes of rotation mutually inclined in the same plane and intersecting at substantially the common center of curvature of the surfaces of the co-acting members, one of said co-acting members being mounted concentrically on its driving spindle, and means for causing the other of said members to be moved by its driving spindle bodily in a circular path on and about the surface of the first mentioned member, said means comprising a crank arm on the spindle, and a crank pin adapted to engage and move the member, said crank pin being adjustable substantially in a direction toward or from the point of intersection of the axes of the driving spindles.

5. Apparatus for grinding and polishing spherically curved surfaces, comprising a pair of csi-acting Work and tool members, one having a convex and the other a concave surface, pair of rotary driving spindles for actuating said co-acting members, said spindles having their axes of rotation mutually inclined in the saine plane and intersecting at substa-i' l, the common ceuter of curvature the surfaces of the coacting members, one of said co-acting members being mounted concentrically on its driving spindle, and means for causing the other of said members to be moved by its driving spindle bodily in a circular path on and about the surface of the first mentioned member, said means comprising a crank arm on the spindle, and a crank pin adapted to engage and move the member, said crank pin being mounted to be movable laterally to facilitate access to or removal of either of the tivo co-acting members.

G. Apparatus for grinding and polishing spherically curved surfaces, comprising a pair of (zo-acting Work and tool members, one having a convex and the other a concave surface, a pair of rotary driving spindles for actuating said co-acting members, said spindles having their axes of rotation mutually inclined in the same plane and intersect,- ing at substantially the common center of curvature of the surfaces of the co-acting members, one of said co-acting members being mounted concentrically on its driving spindle, and means for causing the other of said members to be moved by its driving spindle bodily in a circular path on and about the surface ofthe lirst mentioned member, said means comprising a crank arm on the spindle, a crank gin adapted to engage and move the member, said crank pin being mounted to be swung laterally about an aXis offset from the axis of the spindle to vary the radius of its orbit, and adjustable means for determining the lateral position of the crank pin When the apparatus is in operation.

7. Apparatus for grinding and polishing spherically curved surfaces, comprising a pair of co-acting 'ivork and tool members, one having a convex and the other a concave surface, a pair of rotary driving spindles for actuating said co-acting members, said spindles having their aXes of rotation mutually inclined in the same plane and intersecting at substantially the common center of curvature of the surfaces of the co-acting members, one of said co-acting members being mounted concentrically on. its driving carried eccentrically by the other spindle for engaging the other of said members to move the same bodily in a circular path on and about the surface of the first-mentioned member, said engaging device being' adjustable in a direction toward and from the point of intersection of the axes of the spindles, and the spindle carrying' tlie concentric member being adjustable lengthwise for bringing the center of curvature of the member carried thereby into position to coincide with the point of intersection of the axes of the spindles.

13. Apparatus for Arindiire` and polishing spherically curved surfaces. con'iprising a pair of co-acting Work and tool members, one having' a convex and the other a concave surface, and a pair of rotary driving spindles for actuating said co-acting members, said spindles having their axes of rotation mutually inclined in the same plane and intersecting' at substantially the common center of curvature of the surfaces of the co-acting members, one of said {3o-acting' members being mounted concentrically on its driving spindle, and the other of said members beine' connected to its driving' spindle eccentrically so as to be moved thereby bodily in a circular path on and about the surface of the first-mentioned member, the spindle carrying the concentrically mounted member being provided with a socket, and the member carried thereby having a stem to extend into said socket, the length of said stem being proportioned according` to the curvature of the surface of the member to cause the center of curvature of the. surface of the member to be located at the point of intersection of the axes of the spindles.

lil. Apparatus for grinding and polishing spherically curved surfaces, comprising' means for driving a pair of co-acting work and tool members, one having a convex and the other a concave surface, said means including a rotary driving spindle, a crank arm on said spindle, a second arm carried by said crank arm and connected thereto by means permitting it to swing about an axis in a plane perpendicular to the spindle, an engaging' device for engaging and moving one of said co-acting members carried by said second arm at a point which is eccentric to the spindle axis and normallyy on the opposite side of the spindle axisfroin the point of pivotal connection of said second arm to the crank arm, a spring tending to move said crank arm to press: the engaging device in the direction toward the center of curvature of the surfaces of the co-acting members said second arm also being mounted to swing transversely to the axis of the spindle to carry said engaging device away from its operative position, and means for holding said second arm against such transverse movement to maintain said engaging device in operative position, said means being` adjustable for varying the operative position of said second arm to vary the radius of the orbit of the engaging' device.

l5. Apparatus for grinding` and polishing' spherically curved surfaces, comprising a pair of co-acting work and tool members, one having a convex and the other a concave surface, and a pair of rotary driving` spindles for actuating said co-acting members, said spindles having their axes mutually inclined in the same plane and intersecting at substantially the common center of curvature of the surfaces of the co-acting members, one of said spindles being mounted so that it may be swung about an axis which extends substantially perpendicular to the plane of the axes of the spindles and passes substantially through the point of intersection of the axes of the spindles, one of said co-acting members being mounted concentrically on its c riving spindle, and the other of said members being' connected to its driving spindle eccentrically.

16. A multiple unit machine for grinding and polishing spherically curved surfaces, comprising a plurality of pairs of rotary driving spindles for actuating a plurality of pairs of co-acting work and tool members` the spindles of each pair lia-ving their axes of rotation mutually inclined in the same plane and intersecting at substantially the common center of curvature of the surfaces of the pair of co-acting' members actuated thereby, and the points of intersection of the axes of the several pairs of spindles being alined, and means for simultaneously varying the inclination of the axes of all the pairs of spindles by movement of the corresponding spindles of each pair about an axis which passes through the point of intersection of the axes of the spindles.

17. Apparatus for grinding and polishing spherically curved surfaces, comprising' a pair of coacting work and tool members one having a convex and the other a concave surface; means for imparting a concentric rotary movement to one of said members; and moving means for the other of said members, including an element constrained independently of the contact between said members to move in a circle, Whose axis is inclined to the axis of rotation of the first said member and intersects said axis substantially at the common' center of curvature of the coacting spherical surfaces of said members, an element engaging said second member, and a spring coacting between said elements topress said second member against said first member.

18. Apparatus for grinding and polishing" spherically curved surfaces, comprising a pair of coacting work. and tool members', one

having a con-Vex and the other a concave surface; means for imparting a concentric rotary movement to one of said members; and moving means for the other of said members, including an element constrained to move in a circle whosev axis intersects the axis of rotation of the first member substantially at the common center of curvature of the surfaces of the two coacting members, an element engaging said .second member and mounted to revolve with said first mentioned element and so as to be free to move with respect thereto substantially wtowards and from the common center of curvature of the surfaces of the two enacting menibers, and a. spring coacting between said elements to press said second member against said first member.

19. Apparatus for grinding and polishing spherically curved surfaces, comprising a pair of coactingwork and tool members, one havingI a convex and the other a `concave surface; means for imparting' a concentric rotary movement to the convex member; means for moving the concave member bodily iu a circular path, said means including an element constrained independently of the contact between said members to move in'a circle whose axis intersects the axis of rotation of the convex member at an acute angle and substantially at the common center` of curvature of the surfaces of the two coacting members, and a connection between said element and the concave mem ber; and means arranged to press the two coacting rmembers together with a force which remains constant throughout the circular movement of the second mentioned member.

9.0. i-rpparatus for grindingfand polishingspherically curved surfaces, comprising a pair of cri-acting work and tool members, one having a convex and the other a concave surface, a pair of rotary driving spindles for actuating said co-acting members, said spindles having their axes of rotation mutually inclined and intersecting at a fixed point, one of said membersy being mounted concentrically on its drivingl spindle and the other of said members being connected to its driving spindle eccentrically, and means for adjusting the position of the co-acting members longitudinally of one of the spindles to cause the common center of curvature of the surfaces ofthe two members to coincide with the point of intersection of the axes of the spindles.

21. Apparatus for grinding and polishing spherically curved surfaces, comprising a pair of co-acting work and tool members, one having a convex and the other aconcave surface, a pair of rotary driving spindles for actuating said co-acting members, said spindles having their aires of rotation mutually inclined and intersecting` at a tired point, one of said co-acting members being mounted concentrically on4 its spindle and the other of said members being connected to its driving spindle eocentrically, the spindle carrying the concentric member being adjustable lengthwise for bringing the center of curvature of the member carried thereby into position to coincide with the point of intersection ofthe aires of the spindles.

22. Apparatus for grinding and polishing spherically curved surfaces, comprising da pair efec-acting worlr and tool mt-unbers, v one having a convex and the otherl a concave surface, a pair of rotary driving spindles for actuating said co-acting members, said spindles having their aires of rotation inutually inclined and intersecting at fixed point, one of said co-acting members being mounted concentrically on its driving spindle, and an engaging device carried eccentrically by the other spindle for engaging' the other of said members to move the same, said engaging device being adjustable .in a

direction toward and from the pointof ino tersection of the axes of the spindles, and the spindle carrying` the concentric member being adjustable lengthwise for bringing the center of curvature of the member carried thereby into position to coincide with the point of intersection of the axes of the spindle.

23. Apparatus for grinding and polishing spherically curved surfaces, comprising a pair of co-acting work and tool members, one having a convex and the other a con- 1 cave surface, and a pair of rotary driving spindles for actuating said co-acting members, said spindles having their axes of rotation mutually inclined and intersecting at a fixed point, one of said co-acting members being mounted concentrically on its spindle and the other of said members being connected to its driving spindle eccentrically, the spindle carrying the concentrically .mounted` member being provided with a socket and the member carried thereby having a stem to extend into said socket, the

length of said stem being proportioned according to the curvature of the surface of the member to cause the center of curvature of the surface of the member to be located at the point of intersection of the axes of the spindles.

24. Apparatusv for grinding and polishing spherically curved surfaces, comprising a frame, a pair of opposed spindles mounted on said frame and constrained thereby so ythat their aXes intersect at a fixed point,

v for securing the other end of said/stem to the end of one of said spindles, the: length of the stem being proportioned according to the curvature of the surface of the member to cause the center of curvature of said sur- Jface to be located at the point` of intersection of the axes of the spindles, the other of said co-acting members being connected to its driving spindle eccentrically.

25. Apparatus for grinding and polishing spherically curved surfaces, comprising a pair of rotary driving spindles having their axes mutually inclined in a common plane, one ot' said spindles being angular-ly adjustable about an aXis perpendicular to said common plane and passing` through the point oi intersection oit the spindle axes, and a pair of co-acting Work and tool members, one having a convex and the other a concave surface and mounted on said spindles relatively With the common center of cui'vature of their suriaces substantially at the point of intersection of the spindle axes, one of said co-'acting members being mounted concentrically on its driving spindle and the other of said members being connected to its driving spindle eccentrically.

rseacee 26. A grinding and polishing machine, including a pair oit opposed spindles having their axes mutually inclined in a common plane, one of said spindles being angul'arly adjustable with respect to the other about an axis perpendicular to said plane and passing through the point of intersection or' the spindle axes, and having an offset crank pin.

27. A. lens grinding and polishing machine, including a pair or" opposed spindles,

'one ont said spindles being angularly adjustable With respect to the other and having a crank, and a pin mounted on saidv crank so as to be adjustable towards and 'from the point of intersection of the spindle axes.

28. A lens polishing machine, including a pair of opposed spindles mutually inclined in the common plane, a crank on one of said spindles, and a pin on said crank adjustable towards and away :from the Vpoint of intersection of the axes of said spindles.

VVIL'LIAM TAYLOR. 

